I bought a 1995 lexus sc400 about a month ago. It drove and ran just fine when i got it. has abt 190k miles on it and previous owner gave me a bunch of receipts of all the maintenance done over the past few years. When i got it it gave me no problems. It then sat in my backyard for about a month as i tried to figure out the title bs and get it registered. after i finally figured that out and got it road legal i took it out and it started to stutter when id accelerate a little harder. after it stops stuttering and i stop the car it starts to idle but then it starts to cut out and the engine will shut off on me completely. Starts right back up no problem and ive never had any issues starting it. i've been driving it for around 3 weeks now and its done this about 6-7 times now. It stopped the stuttering but it still has some trouble idling. It's defintely more rare now but it still likes to die on me for some reason. defintely still learning the car so any help would be appreciated. and im happy to answer any other questions abt the car

 

There may be a variety of things tbh. I'm still working through idle issues in my 93 SC4. In your case, could it be bad gas? Did you drain the old fuel and add a fresh tank of gas? Or did you just add gas on top of old gas and away you went? Your ECU may be the issue due to leaking capacitors, but you may want to troubleshoot other things like the fuel resistor/ECU located below the rear window on the driver side. Idle speed control, fuel filter and maybe the airbox leak, which I will start troubleshooting as soon as I'm done with other personal projects I have going on.
I had my ECU rebuilt and it ran fine for about a year, before the low idle, fail to start and dying while driving started coming back. Issues that had been happening prior to the ECU rebuild timeframe. I've been suggested the purchase of a new rebuilt OEM ECU, but I'd rather go a different route, before I spend a grand there.

 

Im at about a quarter tank now so i might try draining out that and adding new gas. But i fill up with the same gas as a close friend of mine who also has an sc300 and he's never had a similar problem but its always better to start simple. I have to redo my rear breaks pretty soon so i'll probably end up digging around to find the problem while i'm already working on it, thanks for the help 👍

 

Check that plastic tube. I started messing with it today and my idle has been normalizing... The plastic tube by the engine, not sure you have the same type I do though.